Packing winds of 170 kilometers (105 miles) per hour, the storm was expected to make landfall on Thursday and sweep up the East Coast.

Emergencies were declared in North Carolina, Maryland and Virginia states, which ordered the evacuation of more than 225,000 residents from coastal zones.

"All preparations to protect life and property should be rushed to completion in the hurricane warning area," the US National Hurricane Center warned.

Washington, which is also in Isabel's path, also ordered precautions. Federal agencies would be closed Thursday and only emergency employees would be expected to work.

The House of Representatives was shutting down and the Senate was closing early, while the White House said it was "working to secure items that may be blown away."

Most train services south of Washington were canceled from Thursday and most schools were to close Thursday and Friday. Transport and other services warned of closures.

Professional baseball, American football, stock car races and golf tournaments were rescheduled across the region.

Most of the people evacuated were on low lying islands just off the coast of North Carolina and Virginia.

In the beach resort of Kitty Hawk, where the Wright brothers flew their first plane 100 years ago, most residents had boarded up and left town.

"Most people are being smart, they're making plans to evacuate, getting their last belongings," firefighter Cole Yeatts told AFP. "We're orienting them toward shelters, but a lot of them are going to stay with family and friends."

Graffiti scribbled on plywood boards left behind read "Take it easy, Izzy" and "Blow, Izzy, blow."

Fred Gentry scrambled to protect his home in sight of the ocean and like most of his neighbours, built on stilts. Gentry pieced together a wall of wood more than one meter (yard) high.

"I got flooded during (Hurricane) Floyd -- seven inches of water in the house. I was not as well prepared. With the wall and all, I hope this time around" luck will be with me, he said. "I'm not a hero, I'm not stupid. I'm out here to protect my property, but I don't plan to stick around too long."

At 0000 GMT Thursday, a hurricane warning was in effect from Cape Fear, North Carolina to Chincoteague, Virginia. The warning meant hurricane conditions were expected within 24 hours.

The center of Isabela was about 450 kilometers (280 miles) southeast of Cape Hatteras, North Carolina, moving north-northwest at 22.5 kilometersmiles) an hour, twice as fast as Tuesday.

"The center of Isabel is expected to make landfall in eastern North Carolina during the day Thursday," the center forecast. "However, the precise timing and location of landfall is uncertain and conditions will deteriorate over a large area well before the center reaches the coast."

Isabel is a strong Category Two storm on the Saffir-Simpson scale, which goes up to five. It can cause flooding, overturn mobile homes and damage roofs and windows on houses.

Michael Brown, head of the Federal Emergency Management Agency (FEMA) said there was a strong possibility of flooding. "That's going to cause a lot of problems," he added.

Hurricane Floyd in September 1999 tore a path of devastation along the North Carolina coast causing damage estimated to be worth six billion dollars. It was blamed for 40 deaths.

More than 62,000 people sought shelters at state facilities, while another 41,000 or more sought refuge in inland motels or with friends and relatives.

TERRA.WIRE